Selective switch



- Oct'. 14, 1930. n.lN. wALTERs Er AL SELECTIVE SWITCH Filed July 29, 1927 2 Sheets-Sheet l ira/5 A4 ML rms A rra/wir Oct. 14, 1930. J. N. wALTERs E'r AL SELECTIVE SWITCH Filed July 29, 1927 2 SheetS--Sheeil 2 J/wfs /V MLE/s [06,45* /7. ULM/f firm.

' Arron/vn l/wfA/rans Vthe switch' shaft t0- normal positiona downV v drive switchmagnet is provided. which whenV energ1zed, gpresse s` 4the switch I shaft against a second constantly driven power drum.` For determining the particular set of brusheson the switch shaft to be employed, Aatrirrping spindle is provided as described in the patent to Craft et al. 'A plurality ofcommutatorenv are-provided similar to those disclosed in the aforementioned patent.- Brushes yare driven over these commutator surfaces' by the vertically ,disposed switch shaft vlhereinbeore' 7 mentioned for driving the brushes having ytors disclosedl herein are arranged to act as a l' access'to the bank terminals. The commutaprogressionswitchv iny addition to acting as an interrul'lt'er.vv {The top porti-on of the com- Vmutator is Athereforeseparated lfrom they bottom'portio'n otthecommutator for the establishmentot diierent circuit conditions durwiring thei'.progressiony of the brushes over the commutator surfaces. are mounted l1n any'suitable mannerbelow the commutator brushassembly. The weight `of the brushfassemblyfand shaft maintains the contacts -open during the time'that'theV brush assembly Visresting in 4its normal posiy. tion.' Theupward'.movement of the brush assembly permit-s the lod normal'contacts to be closed by the movementof spring contacts.

jTherelays disclosed as" part ofthe apparatus Y Aforcontrolling.this switch are a; type /well kno-wnlin the art.j Y

n, isfbeueved emule niveau@ 'wur be A bet-ter understood from the following detailed description takeny together 'with thek illus` tratedembodimentj.

Assuming that the` su Y, the'recei'ver is removed.from thevswitchhook andthe dial .manipulated inthe vwell f known manner. 'The' district selector Aand j'sender :are associated jwith' subscribers staftion X inrespon'se'tothefremoval of the receiv'erf from vthe switchhook las described*V in ftheaforementioned. patent to Lundelll` lThe "'manipulationot the dial. sets a plurality of l "The districtselectorv isoperatedinaccord-Y n 4 this type is to operatethe returnto normal registers `in'ithesender' Vfor the control of the tion XwithstationY.

selective switches or'the association of sta- 'i ance withl .the settings of the' sender registers forpositioning brushes 120,121 and 122 onV the ,trunk terminals 123,124 vand v125 in the manner described in thekaforementioned pat- A i ent 'to'Lundell The sequence switch cams l f5`112,1iaand`114 are rotatedint'oposition 1o for vtheu control of other yselector switches., WVith the'apparatus of the district and senderV "terminals by other district selectors.

Ofi normal contactsv y Y n A bscriber at station yX' desires fa "telephone connection with station thus positioned, a busy potential is associated with terminal 125 through brush 122 andrcam 1 14 to prevent the seizure of the samAe bridge circuit known as the fundamental circuit is established in the sender for energia ing the apparatus of the selective switch, Fig. 2. This `fundament-al circuit may "be .traced i'rombattery through the windingo'f relay v221, section Gr of commutator 244, `brush 253, brush 250, section A fc'ommu'tator 241, thence overV the tipconductor of the trunkextending to terminal 124, brush 121, right upperjand lower contacts of cam 113, normal contact ot counting relay 152, cam

115, winding of stepping relay y151, right upper and lower contacts of cam 112, brush120,

terminal123, thence overthe ring trunk conductor, uppermost normal Contactv of relay 222, section C of commutator 242, brush v251, lbrush 254, commutator 245, terminall25,

brush122 to ground through cam 114. Relay 221 is operated over the undamental'cin cuit as traced.

The operation Voltrelaly 221 establishes a Vcircuit for the up drivevmagnet 262 which may: be traced from battery, through the winding of the up drive. magnet, left normal contact otirelay 223, .right outermost Contact of relay 221, to ground through terminal 125, 7

brush 122 and cam 114'. Since all of the brushes associated with thecommutators 24() n Y' ltrol ot the up drive magnet.` The initial up- -ward movement of the commutator brushes and contact brushes is for making brushfselection as will be hereinafter, described.

' Preceding the upward Vmovement ofthe brushes the oli normalcontacts225 and'226 'are maintained' open by the Vpressure of .the brush assembly against the contact spring assembly 224. Upon'the upward movement oi the brush assembly .the ofi' normal spring asfn sembly is releasedV allowingthe contacts 225 and 226 to be' closed. An operating circuitis thus established for relay'223 from*l battery, vthrough resistance 228, winding ot relay 223 to ground through contact 226.' 1 This circuit is, however, maintained ineffective forfoperating relay 223 by the ground Vshunt Vassociated therewith through cam 114; Relay 223 thereforecannot operate until brush 122 is disconnected from termin-al 125.

The usual practice'inselective switches of relay when the switchis seizedr tor a telethe restore to normalY apparatus such asthe completed.

'down drive magnet. Otherwisethe relay in its non-operated osition would maintain' the restore to normalJ apparatus operated. The usual practice is therefore to establish the restore to normal circuits through a progression switch after the sleeve relay, such as 223, is operated so that when this relay is released the restore to normal circuits will be In this circuit the restore to normal relay 223 'is maintained in its non-operated position in order to obviate the necessity 'ofpreparing the restore to normal circuitsthrough a progression switch commutator. They unusualr circuit'arrangement?v for relay 223, however, eliminates the necessity for such a progression switch circuit.

lt will be remembered that the Lip-'drive magnet 262 was energized, by the operation of relay 221, for brushlselection.y Let it be assumed that the sender isset for the selection of a terminal in the third bank of terminals. The brushes will be elevated to a point where the brush associated with the thi-rd bank will be tripped.` As brush 252 is driven oversection E'of commutator 24?, impulses are intermittently transmitted to the sender. This impulse circuit may be traced from ground through cam 114, brush 122, terminal 125, commutator 245, brush 254, brush 2.52, section E of commutator 243, upper middle contact of relay 222 to the tip conductor for 4 establishing a shunt to release the steppiwy y relay 151 of the sender. The relay 221 is not release-d by this shunt circuit since a circuit is established through its left Contact and winding to battery for maintaining it in anoperated position. Since the sender is set for selecting the third brush it necessarily follows that three counting relays in the sender must be operated to open the fundamental circuit for arresting the move-ment of the up-drive magnet. Each' time the stepping relay 151 is caused to operate and release a set of counting relays is operated. The brush 252 is driven over conducting and non-conducting' segmentsV ,of section E of commutator 243. Each conducting segment of the cemmutator associates the shunt ground with the tip trunk conductor for causing the release of the stepping relay 151. Upon the third connection of they shunt ground to the tip conductor a terminating counting` relay shown as relay 152 is operated to open the fundamental-circuit- The circuit for relay 221 is thus opened when the brush 252 is driven onto the next non-conducting segment of the commutator. The release of rela-y 221 opens the energizing circuit for' the up-drive magnet to arrest the upward movement of the brushes.

It will be noted that the brush 255 is normally disassociated from section K of commutator 246., This brush is, however, associated with 'the commutator during brush selection. Upon the release of relay 221e circuit is established through this brush for the operation of relay 222. This circuit may be traced from battery, through the upper winding of relay 222, right innermost contact of relay 221, right normal contact of relay 223, section K of commutator 246, brush 255, brush 254, commutator 245 to ground through terminal 125, brush 122 and cam 114. The operation of relay 222 establishes an energizing circuit for the trip magnet y26() from battery through its winding toground through the lowermost contact of relay 222.

yThe operation of relay 222 further prepares al path for the reestablishment of the fundamental circuit for the reoperation of relay 221. As soon as the sender sequence switches have been advanced for the control of the switch Fig. 2 foi-*group selection, this fundamental circuit is completed by the release of the counting relays. The fundamen-` tal circuit may now be traced from battery, through the winding relay 221, section G of commntator 244, brush 253, brush 250, section A of commutator 241, thence over the tip trunk conductor, terminal 124, brush 121,-right upper and lower contacts of cam 113, normal contact of counting' relay 152, cam 115, winding of the stepping relay 151, right upper and lower contacts of cam 112, brush 120, terminal 123, to ground through the uppermost Contact of relay The operation of relay 221 establishes a locking circuit for relay 222 before the contact is opened through which its operating circuit is established. This locking circuit may be traced from battery, through the lower winding of relay 222, right middle contact of relay 221, to ground through the lowermost contact of relay 222.

The operation of relay 221 further establishes a circuit for the up drive magnet 262 from battery, through its winding. left normal contact of relay 223, right outermost contact of relay 221 to ground through terminal 125, brush 122 and cam 114. Upon 'the upward movement of the switch shaft the tripping of the brushes associated with the third bank terminals takes place. A detailed description of the tripping mechanism and its operation is .Q'iven in the aforementioned patents to E. B. Craft et al., and A. E. Lundell. It is therefore thought unnecessary to include a detailed description of the tripping mechanism in this application.

The upward movement of the brushes carries brush 252 over the remaining conducting and non-conducting segments of section E of commutator 243. These interruptions are, however, not effective for transmitting impulses to the sender since the conductor connected to commutator 243 has been opened at the upper middle Contact of relay 222. When the brush 252 is associated with section F of commutator 243 a ground is then connected to the tip conductor to release the sender stepping relay 151 by. shunt- This shuntcircuit may be'vtracedV from cam 114 through brush 122, terminal V125., commutator 245,v brush 254, vbrush 252, section F of commutator 243, left lcontact of relay 221 to the tip conductor. c The Yrelay 221 is maintained in itsloperated position by a circuit through its left contacts and winding to battery. The number of impulses transmitted to the sender for shunting the stepping relay V151` depends upon the terminal group to be gizing circuitV for relay 222 that was established through its lower winding. The brush 232 is now associated with the first-terminal of a group of trunks. lf this first trunk is busy the brush 232 willfbe associated with a busy ground connectedto terminal 233. This ground maintains an energizingcircuit for relay 222 over the upper inside contact of .relayf222, right outer normal contact of relay 223, right inner normal contact of relay 221, upper winding'of relay222 to battery. The

Venergizing circuit for the up drive magnet 262 is now extended from battery, through its winding, left normal contact of relay 223, lower inside contact of relay 222, section. D of .commutator 242, `brush 251, brush 254, commutator .245, to ground through the terminal125, brush 122 and cam 114. A circuit for ,the up drive magnet 262 is thus maintained to drive the brushesupward in search of an idle trunk. Ground is not associated with terminal 233 ofV an idle trunk. Therefore when an idle trunk is vencountered the energizinol circuit for vrelay 222 isopened to cause its release. The release of relay'222 opens the circuit for the l up drive magnet to arrest the upward movement of the switch shaft. The release of relay 222 now connects the tip and ring trunk conductors from the sender to brushes 230 and 231 for actuating the yincoming selector switch 280 as described inthe aforementioned patent to Lundell. y

It willl be noted that the commutator brushes have been progressively moved up- -V ward and are now associated with sections of the commutator that ydo not include relay 221 in any circuit. This relay cannot be energized when the fundamental circuit is established for operating the incoming selector switch 280. Certain of the commutator segments and associated brushes therefore act in the capacity of a progression switch for functions similar to those accomplished by ,the sequence switch in the ordinary type of selector switch.- Y Y VIt will beremembered that -an operating circuit has'V been continuously established for` vrelayf223 which operating circuit in ineffee' tive because-of the ground shunt associated with terminal 125.V Let it be assumed now l that the sender has operated to associatethe incoming selector switch 280 with the final selector switch 290v andthe final selector Yswitch with subscribers station Y and also that upon the completion of a' telephone conversation the subscriber at station X has replaced the receiver upon the switchhook. After the replacement of the receiver on the switchhook at station X the district selector 100 is automatically restored to its normal position, thus disconnecting brush 122 from terminal 125. The shunt preventing the op,-

-. eration of relay 223 is thusl removed and this relay is caused-to operate over the circuit previously traced through offnorma'l contact 226. The operation of relay 223associates an energizingcircuit through its right inner contact with the down Vdrive magnet 26,1. The operation of relay 223 further establishesY a circuit to energize relay Y222l from ground through the right outer contact of relay 223, right inner normal contact of relay 221, upper winding of relay 222 to battery. The energization of the down drive magnet restoresthe switch shaft and brushes to their normal position. During the restoring period of the switch terminal 125V is held busy to other selectors by the ground through the winding of relay 223. VThe operation of relay 222 at this time is for the purpose of energizing the trip magnet 260. This circuit may be traced from battery through the winding of the tripping magnet to ground through the lowermost contact of relay 222. The energization ofthe trip magnet maintains the Vtrip lugs inV an angular position with respect to the trip` fingers in order to eliminate the possibility of trouble during the downward movement ofthe switch shaft.

A type of selector known as an oflice selector has been used for the description of this invention. It is not the intention, however, that -the invention shall be'limited to this particular type of selector switch. Y

What is claimed is: V l

1. In a selective switching system, a selectiveswitch having a plurality of.l stationary contacts and movable contacts associable therewith, `means includingY a clutch magnet for driving said movable contacts over the stationary contacts in a primary anda secondaryselective movement, a branched circuit extending through the winding of said clutch magnet, and means in said switch controlled by the primary movement thereof to shift the control of the said clutch magnet from onebranch of said circuit to another.

2. In a selective switching system, a selective switch having a plurality of stationary contacts and movable contacts associable therewith, means including aclutch magnet for driving said movable contacts over the stationary contacts in a plurality of selective movements, a branched circuit extending through the winding of said clutch magnet, and means in said switch 'controlled by the movements thereofy for organizing the branches of said circuit.

3. AIn a selective switching system, a selector switch having a plurality of stationary contacts and movable contacts associable therewith, means including a clutch magnet for driving said movable contacts over said stationary contacts, a branched circuit eX- tending through the winding of said clutch magnet selectable for governing a plurality of progressive selective movements of said contacts, and a circuit changer operated by said driving means for selecting the branches of said circuit. y l

4. In a selective switching .system` a' selector lswitchhaving a plurality of stationary contacts vand movable contacts associable therewith, a .progressionswitch having movable brushes, a common means including a clutch magnet for driving said movable contacts and brushes in a. plurality of selective movements, a ybranched circuit extending through the winding ofsaid clutch magnet, and means controlled by. said progression switchfor shiftingthe'control of said clutch magnet from one branch of said circuit to another.`

' 5. vIn ay selective switching system, a selectorswitch having a plurality of stationary contacts and movable contacts associable therewith, means including a clutch magnet for driving said movable contacts over said 'stationaryrcontacta a branched circuit eX- tending through the winding of said clutch magnet 'selectable for governing a plurality of progressive selective ,movementsv of said contacts, electrically operable apparatus for shiftingy the control of said clutch'magnet from one branch of said circuit to another, and a device controlled by said clutch magnet for variably operating said apparatus.

i 6. In a telephone exchange system, a first switch, a second switch, means operable for causing said first switch to select said second switch, means for operating said second switch,'an electro-magnetic device operative forrestoring said second switch, an operating circuit for said electrosmagnetic device, meansr for establishing said operating circuit during the operative movements of said second switch, and means maintained by the connection of said 'first switch to said second switch for causing said operating circuit to be ineffective. Y

7. In a telephone exchange system, a first switch, a second switch, means operable for causing said first switch t-o select said second switch, means for operating said second switch, an electro-magnetic device operative for restoring said second switch, an operating circuit for said electro-magnetic device, means for establishing said operating circuit during the operative n' ments of said second vitch. means maint. ,ned b v the connection of said first switch to said second switch for causing said operating circuit to be ineffective, and means whereby said circuit is made effective for operating said electromagnetic device by the disconnection of said first switch from said second switch.

8. In a. telephone exchange system, a first switch, a second switch, means operable for causing said first switch to select said second switch thereby associating a busy potential with a terminal of said second switch, an electromagnetic device in said second switch operative for restoring said second switch, an operating circuit for said electro-magnetic device established during the operative movements of said second switch, means for associating a busy potential with said operating circuit to maintain said operating circuit ineffective, and means for disassociating said busy potential from said operating circuit for causing the operation of said electromagnetic device to restore said second switch. 9. In a telephone exchange system, a first switch, a second switch, means operable for causingl said first switch to select said second switch, said second switch comprising 'stationary commutators with movable brushes associable therewith arranged to act as both a progression switch and an interrupter for variably governing the selective movements of said switch, means for moving said brushes for switch selections, an electro-magnetic device operative for restoring said second switch, off normal contacts closed by the movement of said commutator brushes for establishing an operating circuit for said electro-magnetic device, and means maintained by the connection of said first switch to set second switch for causing said operating circuit to be ineffective. l

10. In a selective switching system, a selective switch having a drive shaft, a driving means for said shaft, a branched control circuit extendingl through the winding of said driving means, 'stationary contacts varia-bly selectable by movable contacts attached to said shaft, brushes attached to said shaft for controlling the extent of movement of the shaft, and a progression switch with movable brushes attached to said shaft for sequentially closing the bran ches of said control circuit for' selectable by movable contacts attached to saidshaft, an interrupter driven by said shaft forcontrolling the extent of shaft movement, and afprogression switch driven by said shaft for sequentially closing the branches of said drive shaft.

Y 13, In aselective switching system, a selective switch having a drive shaft, a-,driving Ymeans for said'shaft, ya plurality of stationary.contacts, movable contacts attached to said shalt foreassociation with said station ary contacts, a branched control circuit extending through the winding of said driving means for driving said movable contacts over Y said stationary contacts in a plurality of selective movements, and a switchingmechanism operable by the movementl of said shaft for sequentially changing the control of said driving means from one branch of said circuit another and for controlling the extent ot each selective movement. Y e

14. Ina selective switching system, a selective switch having a drive shaft, a driving means for said shaft, a plurality of stationary'contacts, movable contacts attached to said shaft for association with said stationary contacts, a branched control circuit extending through the winding of saiddriving means for driving said movable contacts over said stationary contacts in a plurality `of selective movements, a plurality of electromagnetic devices for establishing the branches of said circuit, and a switch mechanism operable by the movement of said shaft r. 5b for sequentially controlling the energization 'o said electromagnetic devices A for changing the control of said driving means from one branch: of circuit to another.

15. In a telephone exchange -system, a selector switch having a plurality of groups of stationary contacts and sets of movable contacts associabl'e therewith, means including a clutch magnet for driving said movable contacts over said stationary contacts in a plurality of selective movements, a branched control circuit extending through ythe winding of said magnet, stationary commutators,

a set `olf movable brushes associabletherewith and operable by said magnet, and means controlled by theV movement of said set of brushes over said'commutators' kfor sequentially establishing the :branches of said'cir-v cuit and for Vgoverning thels'elective `movements 'of said switch."V e

16. In a telephone exchange` system, a

selector switch comprising a plurality of stationary terminals arranged-in groups, and sets of movable contacts associabletherewith,

means including a clutch magnet for'driving said movable contacts over said stationary terminals to select any group of terminals and an idle terminal in the selected group, a branched control circuit extending through the winding of said magnet, stationarycommutators, a set of movable brushes associable therewith and'operable by said magnet, and `means controlled by the movement of said set of brushes over said` commutators for sequentially yestablishing the branches of said circuit land for governing the selective movements of said switch. c Y .Y 17; In a telephone exchange. system, a selector switch comprising aA pluralityhof stat1onary terminals yarranged in groups in a single plane and sets Lof movable-contacts associable therewith, Y meansl r:includingV a clutch magnet for' driving said movable contacts over said'stationary terminals to select any group of terminals and anV idle terminal 1n the selected group, abranched control circuit extending through the winding of said magnet, stationary commutators, a set of movableY brushes associabletherewith` and operable by said magnet, and means. controlled by the movement'of said set of brushes over-said commutators for sequentially establishing the branches of said circuit and forV governing the selective movements of said switch. Y

18. In a telephone exchange system, a selector switch comprising a plurality of stationary banks of terminals arranged in groups and sets of movable contacts associable respectively with said banks of terminals, means including a clutch magnetfor driving said movable contacts first forselecting a set. of movable contacts and thenin group and terminal selection movements to select any group of terminals in any one of said banks and an idleterminal in the selected group, a branched control circuit extending through the winding of said magnet, stationary commutators,` a set of movable Vbrushes vassociable. therewithA and operable e by sa1d magnet, and means controlled by the Vmovement oi. said set of brushes over said ments of said switch, and means controlled by the movement of said set of brushes over said commutators for sequentially establishing thev branches of said circuit and for transmitting revertive control' impulses to said sender.

In Witness whereof, We hereunto subscribe our names this 22nd and 26th days of July,

' EDGAR H. CLARK.

JAMES N. WALTERS. 

